It started suddenly a couple of months ago.

One night, while lying in bed after we had turned the lights out, my 10-year-old son burst into tears.

"I am scared of dying," he said in between sobs.

"I don't want to be reincarnated and start all over again. I also don't want to stop existing."

I tried to soothe him by spouting the usual platitudes - that all living things must die, but that his time was still not up and would not be for a long while; that he was healthy and safe, and had parents, grandparents and teachers to protect him at all times.

I tried to couch death in positive terms, that eternal life would make human beings careless and complacent, no longer needing to seize the day and make the most of themselves.

As he drifted off to sleep, somewhat mollified, I suggested we draw up a bucket list the next day to remind ourselves of all we want to and can accomplish before The Big Sleep.

Later, listening to his even breathing in the dark, I thought about how the world must seem to a 10-year-old, with its mysteries and complexities. I had to admit that I had no idea what tomorrow would bring, much less how to answer my child's questions about what happens after we die.

How equipped was I to help a young boy worried about what would happen when the end comes? There is a name for this fear of death: Thanatophobia.

Sigmund Freud theorised that this fear masked deeper concerns.

The father of psychoanalysis believed that no one believes in their own death, so this fear was merely a disguise for unresolved childhood trauma.

Yet, what happens when a child, whose death still lies far in the future, begins to believe in its imminence?

As the weeks passed, my son's thoughts about death intensified.

On a trip to Bali, after a fun day of sea and ice cream, he appeared by my bed in the middle of the night, crying. The thoughts would not leave him alone. Does God exist? Does Heaven exist? Where do we go after the body and mind give out? Who will remember us?

In the middle of play, he would suddenly look up and say: "The thoughts are back."

We tried distraction - soothing music, meditation, breathing exercises, Taylor Swift albums. At night, he fell asleep in front of the TV. Watching science programmes seemed to comfort him.

Young kids, more often boys, are rarely good at expressing why they feel certain complicated emotions.

Many times, they may not even understand what they are feeling.

Eventually, I managed to coax out of my son what first gave rise to his anxiety about death.

My maternal grandmother - his "Lao Ma" - died the day after last Christmas.

She had been a quirky 88-year-old, but was bedridden and ailing after a hip fracture.

My two sons had gone to her wake, but I had decided to keep them home during the funeral and cremation. I was concerned that they might not be ready to see the outpouring of grief among adults.

I now wonder if my elder son missed the chance to say goodbye to her properly.

I explained to him once more that we should be glad Lao Ma was no longer suffering.

But my son remained unconvinced. "Why can't we live forever?" he asked.

Together, we read articles on the Internet about the implications of eternal life: a foggy, declining mind trapped in a undying body would be no fun; people around you would be afraid of you and treat you like an outcast if they ever found out, and so on. Still, when night came again, so did the "thoughts".

As parents, we try our best to guide our children through the world, answering their incessant questions. But when it comes to queries about mortality and theology, I cannot pretend to know anything for sure.

While I hope that my son's thanatophobia is a phase - it is common for kids around three or four to be morbidly curious or anxious about the topic; less common, perhaps, is the existential crisis that seems to have hit my melancholic firstborn - I am also certain that this is an issue he needs to find the answer for himself as he grows up.

But Freud, it turned out, was right. A few days before I was due to leave for a three-month trip to South Korea on a writing residency, my son finally blurted out possibly what was eating at him all that time.

"I don't want Mummy to go," he said. "You're going to a dangerous place. I don't want to have no mummy." Somehow, the boy had overheard me discussing North Korea firing missiles, and the escalating tensions between the two Koreas, and he got it into his head that I would be bombed.

To reassure him, I checked online and showed him that there were no advisories against travelling to Seoul. I registered with the Ministry of Foreign Affairs and notified it of my travel itinerary, obtaining the ministry's travel emergency number.

"If anything happens," I told my wide-eyed boy, "Singapore will come and help me."

He giggled as he imagined a military helicopter going to airlift his clumsy ol' mum.

Then, for good measure, I bought the most comprehensive travel insurance plan I could find.

That seemed to do the trick.

For now. It is hard leaving a boy who is paranoid about his own and your demise.

Fortunately, I have a supportive spouse who understands what needs to be done to help our son cope. When in doubt, give a bear hug. My great friend, the boys' Auntie Jojo, has also offered to be a listening ear, just a phone call away.

And there is always Skype, daily.

After all, death, like life, can be taken only one day at a time.

•Clara Chow is a writer and co-founder of art and literary journal WeAreAWebsite.com